The movements of tracer particles in labyrinth channel under dynamic and constant water pressure were observed based on partical track velocimetry (PTV) technique. Water flow characteristics in labyrinth channel were analyzed and the anticlogging mechanism of drip irrigation system under dynamic water pressure was discussed. The results show that when comparing with constant water pressure, flow rate in the channel under dynamic water pressure did not decrease significantly. Therefore, the effect of dynamic water pressure on water delivery capacity of drip irrigation system was not obvious. While the flow velocity in channel’s main flow path fluctuated dramatically under dynamic water pressure supply system, and the turbulence was more intensely. Most particles could pass the main flow path quickly and the residence time of tracer particles reduced significantly. The flow velocity in the flow stagnation zone was relatively low while the turbulence remained strong. So the particles can hardly deposit in the flow stagnation zone due to the remarkably fluctuation. Meanwhile, some particles in the flow stagnation zone returned to the main flow path and finally flew out of the channel, which lead to the significant decreasing possibility of particle deposition in the channel. Therefore, dynamic water pressure could improve the anticlogging performance of drip emitter effectively.